The invention generally relates to a feeding device for electric components held in a plurality of tapes. More preferably, it relates to one where it is possible, in each case, for a belt to be driven by use of a transport wheel, which is coupled to an electric motor via a step-up gear mechanism.
EP 0 589 275 A1 has disclosed a feeding device for taped electric components in which transport pins of the transport wheel engage in transport holes in a tape and drive the latter step by step in such a way that the components, held in pockets, pass successively to a collection position, in which they can be removed by a gripper belonging to an automatic pick and place machine for electric circuit boards. The transport wheel is operated by a drive motor via a worm gear mechanism and a spur gear mechanism. The motor axis is located on that side of the spindle axis of the worm gear which faces the tape. Since, here, the drive motor needs a complete revolution or an integer multiple of a complete revolution during each step by use of a moveable stop, a corresponding step-up ratio has to be set, which is made possible by the spur gear mechanism.
The Siemens company publication 0 299-S-23-500-d, Issue 1, page 12, also discloses a feeding device in which two narrow tapes can be handled in one feeding device. In this case, separate drive devices according to EP 589 275 A1 are used for the individual tapes. It is common to keep the thickness of the drive motors as low as possible, since two of the motors located in parallel beside each other find space within a housing of the feeding device. Doubling the component tracks has the advantage of low overall costs with only one housing which, because of its greater width, can be constructed to be particularly dimensionally stable.
On pages 2 and 3 of the aforementioned company publication, a pick and place concept is described and presented in which a turret-like pick and place head is provided with a large number of grippers that project in the manner of a star. If a large number of components of the same type are needed, then the pick and place head can be cycled onward very quickly from gripper to gripper without having to change its position. In order to be able to drag the components correspondingly quickly, the drive motor of the feeding device has to have the largest possible diameter in order to be able to provide the corresponding drive power.
An embodiment of the invention is based on an object of being able to increase the thickness of the drive motors.
As a result of the offset of the motor axes, the drive motors can overlap laterally in the axial direction of the transport wheels, so that the motor thickness and therefore the power of the motors can be increased. In particular, it is possible to increase the overall thickness of the motors to a dimension which is greater than the outer width of the feeding device. Therefore, the cycle rate in each of the tapes can be matched to an increased cycle rate of the turret head, which is reflected in a corresponding increase in the performance of the automatic pick and place machine.
A self-locking worm gear mechanism can make it possible to arrange for the motors to be switched on only during the drive phase and to be switched off outside the phase. Therefore, in spite of the increased power, the heat loading of the motors and of the feeding device can be reduced to a non-damaging level.
Further, it is possible to disentangle the drive motors in terms of their geometric arrangement in a straightforward manner.
In addition, the motors can remain oriented in a single direction, which makes installation easier. As a result of their parallelism, the entire envelope volume remains low.
Also, the number of motors and therefore the number of drive wheels and of tapes can be increased considerably, with constant external dimensions. This makes it possible, within the predefined placement width of the feeding devices, to increase the number of tracks and therefore the number of different component types.